Construction of Multifunctional Fe 3 O 4 -MTX@HBc Nanoparticles for MR Imaging and Photothermal Therapy/Chemotherapy.

To accomplish effective cancer imaging and integrated therapy, the multifunctional nanotheranostic Fe3 O4 -MTX@HBc core-shell nanoparticles (NPs) were designed. A straightforward method was demonstrated for efficient encapsulation of magnetic NPs into the engineered virus-like particles (VLPs) through the affinity of histidine tags for the methotrexate (MTX)-Ni2+ chelate. HBc144 -His VLPs shell could protect Fe3 O4 -MTX NPs from the recognition by the reticuloendothelial system as well as could increase their cellular uptake efficiency. Through our well-designed tactic, the photothermal efficiency of Fe3 O4 NPs were obviously improved in vitro and in vivo upon near-infrared (NIR) laser irradiation. Moreover, Magnetic resonance imaging (MRI) results showed that the Fe3 O4 -MTX@HBc core-shell NPs were reliable T2 -type MRI contrast agents for tumor imaging. Hence the Fe3 O4 -MTX@HBc core-shell NPs may act as a promising theranostic platform for multimodal cancer treatment.